PCV, EGR, and Oil Separator Membrane Repair Kits for Reliable Crankcase Ventilation
If your BMW hisses at idle or you find oil in the intake, a targetedPCV diaphragm repair kitor amembrane valvecoverreplacement is often the fastest way to fix the root cause. Klifex focuses on BMW fitments such as M52, M54, N52, N54, N47, N57, B47 and B57, and we also supply membrane kits for VW, Audi, Porsche, Volvo, Land Rover where needed.
What the PCV / EGR System Does
Start with the simple idea: the PCV system keeps the engine at the right internal pressure. It takes blow-by gases and oil vapor out of the crankcase and routes them back into the intake. The PCV valve, diaphragms, and oil separator membranes control flow and trap oil mist. When a membrane or valve fails, the unit either leaks vacuum or overpressurizes the crankcase. Both situations cause rough idle, oil in the intake, and diagnostic codes.
On turbo cars, failed parts speed up DPF loading and sensor fouling, so sealing and separation matter more than they look. Turbos, intercoolers, and DPFs hate oil contamination very much. Replacing a simple membrane or valve often prevents much larger jobs and money loss in the future.
When You Need a PCV or Crankcase Breather Repair Kit
Choose aPCV diaphragm repair kit orPCV hose kitwhen the diaphragm is torn or a breather hose is visibly cracked. Order a membrane valve cover replacement for BMW M52, M54, and B47 families when inspection shows a damaged membrane or separator. Pick a full crankcase ventilation kit or crankcase breather kit when multiple seals leak or the separator housing is damaged.
Here are the clear signs that the ventilation system needs attention:
Rough idle, stalling, or unstable RPM.
Whistling or hissing from the valve cover or breather hoses.
Excessive oil consumptionor oil in the intake or intercooler.
Visible oil leaks from valve cover gaskets or separator housings.
Vacuum leak symptoms and lean codes on the scan tool.
If you see one or two of these, inspect the diaphragm and hoses. If multiple signs appear, plan a kit replacement plus intake cleaning.
Note! Consider aPCV bypass kitorPCV valve delete kitonly for dedicated race or off-road use. If you are unsure which approach is right, start by isolating the failure: is it a single hose, the diaphragm, or the separator housing? A targetedrepair kitis usually faster and cheaper, but when several items are aged, a full kit prevents repeat work.
Benefits of Using a PCV Diaphragm or Breather Kit
A proper kit brings practical gains:
Restores correct crankcase pressure and steadies idle.
Stops vacuum leaks and the hissing that signals a torn membrane.
Reduces oil consumption and keeps oil out of the intake.
Costs less than replacing a whole valve cover, and fits by engine code.
Helps turbo engines remain reliable under boost.
Beyond the immediate fix, using an engineered repair kit improves long-term reliability. New elastomers and correctly sized O-rings reduce the chance of recurring leaks and prevent oil vapor from degrading sensors and DPF systems. For DIYers, a well-packagedBMW kitmakes installation straightforward and repeatable
Types of PCV and Breather Repair Kits
PCV diaphragm repair kits, such asPCV membrane BMW E39/E38andvalve cover membrane BMW B47/B57, replace the membrane, spring, and seals. Crankcase breather kits include reinforced hoses, check valves, and fittings for reroutes or replacements.PCV hose kitsand elbow kits replace brittle factory tubing.
Oil separator membrane kits and EGR diaphragm replacements restore separation on BMW and European engines.Catch can and breather platekits provide supplemental oil control on high blow-by applications.
What’s Included in PCV and Membrane Repair Kits
Kits typically include oil-resistant diaphragms, springs, O-rings, gaskets, reinforced hoses or elbows, and small mounting hardware. Klifex often uses upgraded elastomers for high-temperature and oil resistance. Parts are produced to fit specific engine codes, so installation is straightforward and repeatable.
Why Choose Klifex Membrane and PCV Repair Kits
Klifex focuses on BMW-matched kits with clear engine-code fitment, upgraded materials, and precise tolerances. That reduces callbacks and speeds repairs for shops and DIYers. Order by engine code or VIN to get the exactPCV repair kit,PCV diaphragm repair kit, ormembrane valve coveryour car needs.
FAQ
Selecting the correct PCV, EGR, or oil separator membrane requires matching it exclusively to the original part number of the specific component where the membrane is housed. Since manufacturers often update internal designs mid-production, we also strongly recommend a thorough visual comparison: if your current unit is a 100% visual match to our product photos, the kit is exactly what you need. Taking these steps ensures your new membrane fits perfectly and restores your engine's ventilation to factory-spec performance.
Valve-cover membranes seal crankcase ventilation under the cover. Oil-separator membranes trap oil mist before it enters the intake. EGR membranes meter exhaust-gas recirculation. Intake-actuator membranes drive vacuum-controlled flaps in the manifold. Use the site’s membrane-type filter to zero in on your exact variant.
A torn or hardened membrane often causes rough or erratic idle, hissing leaks, oil pooling in the intake, and crankcase pressure. You may also see smoke or oil weeping around the cover. Fixing it stops gasket failures, improves driveability, and protects the engine from blow-by damage.
If the main components are in good condition (no torn or hardened diaphragm), a membrane-only solution will suffice. However, if you notice a cracked cover, warped matting surface, clogged separator passages, or repeated failure, it's time to replace the full assembly.
Yes. Just make sure your workspace stays clean first, without any unnecessary components up to small caps. Ensure proper seating and orientation. After replacement, perform 2-3 additional tests to detect leaks.
We understand that getting your "rig" back on the road is a top priority, so we strive to process every order as quickly as possible. In most cases, your package will ship the very same day the order is placed, depending on the time of purchase. If the order is received later in the day, it will be dispatched no later than the following business day.
The delivery timeline for your order depends on which fulfillment center is handling your shipment. Domestic orders shipped within the U.S. are dispatched via USPS Ground Advantage, which typically takes about 3 to 5 business days to reach your door. For international shipments departing from our Ukraine facility, Ukrposhta provides worldwide delivery that generally takes about two to three weeks to reach almost any location on the globe. We aim to get your "rig" back to factory-spec performance as quickly as possible, regardless of where you are located.
Kliffex operates two strategic fulfillment centers—one in Ukraine and one in the United States—to get your parts to you as efficiently as possible. Depending on which warehouse has your items in stock, your parcel will be dispatched via a specific carrier: orders from our U.S. location are shipped via USPS, while international shipments from our Ukraine facility are handled by Ukrposhta. To see what is ready for immediate domestic shipping, you can check U.S. warehouse availability by using the special filter on the right side of the page or by following the provided link
At Klifex, we have got your back and your money. We guarantee that if your parcel has not reached you within 40 days through no fault of your own, we will issue a full refund so you do not lose a cent. This peace of mind covers everything except cases where a package is sent back because it sat unclaimed at the post office or in a mailbox due to a lapse in tracking or forgetting to pick it up before the storage deadline expired. Additionally, while we handle the logistics of getting the parts to your country, managing any local customs duties or paperwork is the buyer's responsibility, as failing to participate in that process prevents successful delivery. Aside from those specific situations, we take full responsibility for ensuring your vehicle gets the components it needs.
We provide a tracking number for every order so you can monitor its journey directly to your door. You can track your package using the link provided in your shipping confirmation email, or by visiting the official websites of USPS (for U.S. domestic orders) or Ukrposhta (for international shipments). For the most detailed international updates, we also recommend using global tracking services like 17track or ParcelsApp, which aggregate data from multiple carriers.
